package com.dingding.nettyserver.core.util;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @Description Spring的ApplicationContext的持有者,可以用静态方法的方式获取spring容器中的bean
 * @author fengshuonan
 * @date 2016年11月27日 下午3:32:11
 */
@Component
public class SpringContextHolder implements ApplicationContextAware{

	private static ApplicationContext applicationContext;
	
	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		SpringContextHolder.applicationContext = applicationContext;
	}

	public static ApplicationContext getApplicationContext() {
		assertApplicationContext();
		return applicationContext;
	}
	
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String beanName){
		assertApplicationContext();
		return (T) applicationContext.getBean(beanName);
	}
	
	public static <T> T getBean(Class<T> requiredType){
		assertApplicationContext();
		return applicationContext.getBean(requiredType);
	}
	
	private static void assertApplicationContext() {
		if(SpringContextHolder.applicationContext == null){
			throw new RuntimeException("applicaitonContext属性为null,请检查是否注入了SpringContextHolder!");
		}
	}
	
}
